In September 2014, it was announced that Ambrose would return to V8 Supercars to race a Ford Falcon FG X for DJR Team Penske, formed by NASCAR owner Roger Penske, who was interested in expanding his Team Penske organization to start a team in Australia and as a result merged with Dick Johnson Racing, becoming DJR Team Penske. Ambrose started in 2015. He debuted at the final round of the 2014 season, driving the #66 Xbox-sponsored car. He began the 2015 season on a low note, starting near the back of the field in every one of the race. His best finish was 12th in the 3rd race at the Clipsal 500 in Adelaide.